https://buddingpsychologists.org/factors-influencing-learning-in-children/

An amazing read with lots of insights and well researched. Each child is wired differently and so is their approach and way to learn. 

A supportive environment, just the right challenge, appropriate reinforcements etc are a few things that'll help enhance learning. Also, it is important to consider early intervention and know the signs when a child is showing signs of learning issues. The earlier the signs are detected , with appropriate intervention it can greatly benefit the child.